9
sound(adjective, good, correct, reasonable, reason)
8
valid(adjective, good, sound, right, reasonable)
8
well-rounded(knowledgeable, cultured, educated, erudite, enlightened)
7
well-founded(adjective, good, sound, reason, proper)
6
just(adjective, good, sound, correct, right)
6
reasonable(adjective, sound, correct, reason, proper)
5
cogent(adjective, good, sound, correct, reasonable)
5
rational(adjective, sound, reasonable, reason, forceful)
5
reasoned
4
credible(good, sound, right, reasonable, rational)
4
justified(good, correct, proper, moral, forceful)
4
legal(good, sound, right, reasonable, rational)
4
legitimate(good, sound, correct, right, reasonable)
4
sane(adjective, reason, sane)
4
sensible(adjective, reason, sane)
4
solid(adjective, good, sound, right, reasonable)
4
substantial(good, sound, right, reasonable, rational)
3
good(sound, right, reasonable, rational, genuine)
3
judicious(adjective, reason, knowledgeable, cultured, sane)
3
justifiable(sound, reasonable, rational, logical, understandable)
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APASmart Define. (2016). well-grounded thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/well-grounded/thesaurus/synonyms
ChicagoSmart Define. 2016. "well-grounded thesaurus" https://smartdefine.org/well-grounded/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2016, well-grounded thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/well-grounded/thesaurus/synonyms>.
MLASmart Define. "well-grounded thesaurus" 29 March 2016. Web. 20 September 2026. <https://smartdefine.org/well-grounded/thesaurus/synonyms>